Air Conditioning - New HVAC, still HOT in rooms??... Help!!

I hope someone can help.
We live in a 1700 sq ft. house built in the 60's that we bought a few years ago, located in Sacramento, Ca. The A/C hasn't worked very well (it was the original one) since we moved in so we finally had it replaced last week. It was replaced by a reputable company in our area that's been around for years and has always been known for excellent work.
The company put in a Trane 15i 3.5 ton HVAC unit (13 SEER) along with the heater/blower unit. They also sealed the ductwork with aerosealant. We have dual pane in most of the house except for a couple of small windows.
We've had hot temps these days (NOT UNCOMMON through October) - 105+ each day and the best we can get in our hallway (where the thermostat is) is 83 degrees. We have the thermostat set to 78 but the inside temp rises above that by NOON. As soon as the temperature gets above that the unit is running CONSTANTLY until about 10pm at night when the outside temps reach about 90 deg.
WORSE yet, the family room and the master bedroom get to about 88 deg F. for most of the day!!
I have an accurate industrial grade thermometer and have measured the returns to be at about 82 deg during the hot part of the day and the registers to be at about 64 deg or so. I've checked this a lot during the day and it's always at least a 16 degree spread and sometimes 18 or so.
The company has come out a few times and are scratching their heads - they were careful in calulating the right size A/C and have checked the ductwork - we have good airflow and it's cold... The Trane is operating perfectly they say... But the only place you can live comfortably is in the livingroom where it's about 82 deg.
We have a number of friends/relatives that can keep their houses at **GULP** 75 degrees easy in these same temps... What gives??
PLEASE help! This whole system is new and seems to be working "correctly..." What do we do?
Not only is this new "efficent" unit costing **MORE** to run than our old crusty unit (I check the digital kw meter every day to see what we're using and have compared the numbers) but it's not getting the job done!
Help!!:confused:
Joe

When you say the old a/c didn't work that well the new one may be mirroring the old one's performance.
When they were being carefull in calculating the unit's size did they wind up with the same size as the old one.
Also, when they did this calculation was it on a survey form or in their head.

It is possible that your ductwork is too small to handle the amount of air that each area of your house needs. It's up to your installer to sort this out.
I personally am carefull when installing central air to explain to customers that there is the possibility their existing ductwork may not be optimized for air conditioning.
It takes less airflow when heating than it does for cooling and undersized ducts are quite common.

When they say your unit is working correctly it is not if it can't handle the load.
They should be able to get an idea of what is happening by checking the system's refrigerant pressures to see how hard it is working.

I would keep callimg them to come and sort this out.

They may have done their calculations correctly but what outside temp did they base it on? If they based it on an outdoor temp of say 90º then at 105º it will struggle to keep up. A 15º to 20º drop is ideal so they are in spec there. Like Greg said, did they come up with the same size as your old unit ?

Thanks for the quick replies!
They came up with a bit larger one than the old one - it was a 3 ton, and the new one is 3.5. They've measured the pressures during the hot part of the day, but I didn't ask if it was "correct" for hot days.
As far as if it was calulated, I think they had a pencil and paper, but it seemed as if it was "in their head" at least when I saw them. Not to say that they didn't go back to the shop and pound out the numbers, they did do some initial tape measuring...
After reading so much about people getting "oversized" A/C units I was worried about getting something TOO big, but now after being HOT for a week solid I'm starting to wonder if what else they could do get the temps down. I did ask about the duct work and they seemed to think it was ok.
The bottome line for me was that my wife and I were crystal clear from the get go that we wanted relief from our two hottest rooms that get so hot during the day and was re-assured again and again that "don't worry, when we're done it we would be COLD." I pressed again several times before and after the install that I was worried that we'd see a general improvement, but not get the temps down in the family and master... They assured us that when they got the main temps down the WHOLE house would equalize and we'd be very happy with how cold it was.
We just got the unit installed last Friday (the 21st) - if they put an undersized one in shouldn't they need to make it right by putting in the right size??
They've been out 4 or 5 times trying to get things better (the first time there wasn't enough freeon, and the 2nd time the unit just stopped getting cold AT ALL and they sucked all the freeon out and recharged again from scratch, and the third time they came in and enlarged my return on one side under the heating unit (it's now 50% bigger). The 2nd return is in the family room and it's stuck between the wall so the flow is somewhat restricted, but he did the calcs and said we were now definitely over the minimum needed for adequate intake...
I just want my house cool... We paid 10g for the system and want it to just work... They're getting frustrated too - they've offered to take the new system out and refund our money, but I want it to work...
Can't be a situation where there is "no solution" and we're stuck, can there?
Thanks so much!!
Joe

I'm leaning toward the idea that the duct work is inadequate. Undersized ductwork is more the normal state of affairs these days and this has held true for quite some time.

One tip: If you have a floor-register supply system try removing the register assemblies and letting the air just gush into the rooms. Have the blower set to the maximum speed (it may be excessively noisy) and then take the temperature of the air from the register hole and at the return-air grille. Let it run for a while and see if there is any improvement. You may also want to try removing the return-air grille. Sometimes the RA grill is undersized for the job and seriously restricts the return air flow. Take the temperatures under all of these scenerios and also with the RA grill off but with the floor registers in place.

If any (or all) of these things cause an improvement then your duct system is less than adequate. The fix will depend upon your budget, the layout of the duct system and your tolerance for extra noise.

The company put in a Trane 15i 3.5 ton HVAC unit (13 SEER) along with the heater/blower unit. They also sealed the ductwork with aerosealant.

Lost here just what Trane units do you have there.Is this a heat pump? is the blower a V/S could you have a humidistat on this unit in the stat or at the unit to slow the blower down??
A seer of 13 for where you are Id say should have gone for a higher seer.
ED;)

Thanks for replying.
I don't know about the heat pump part - we have a Trane XR 80 heater/blower constant speed (air handler?) inside the house and the Trane Trane 15i A/C outside the house. The blower is set to high (they told me the last time they were working to make things cooler), so we know that the speed of the fan isn't an issue here...
We were told that since we were going from a SEER of around 6, that we'd see a HUGE improvement in energy usage with a 13...
Today the temps have just about gotten to 100 degrees outside. We've had the thermostat set to 79, and it's holding the hallway temperature at 79, but the two rooms in question are 2 degrees higher (the family room is 6 degrees higher - that room does have 4 computers in it, but all the monitors are LCD's and not CRT's).
The BAD news is that the unit has been solid ON since around 10am and is NOT cycling... The energy bill is going to kill us at
.17 per kwh!
Joe

joebelter

I would insist that your Trane dealer contact area Trane residential specialist to visit your home. Sometimes a fresh set of eyes can find the problem. The Trane XL15i is a very good AC condenser and at 3 1/2 ton should be performing much better than you describe. I have a Trane 3 1/2 ton cooling a home about 1/3 larger than yours and system only begins to struggle when outside temp reaches 100 degs-and that's at a maintained inside temp of 74 deg. What mdl is your air handler?

IMO

if you have a XL15i you should have about a seer of 15 by my books???????? with a 42,000 btu AC.
we have a Trane XR 80 heater/blower constant speed (air handler?) inside the house and the Trane Trane 15i A/C outside the house. The blower is set to high (they told me the last time they were working to make things cooler), so we know that the speed of the fan isn't an issue here...
Now that XR80 comes with 5 different blowers. So do you have a one that is for the 3 1/2 AC?
that room does have 4 computers in it, but all the monitors are LCD's and not CRT's).

Oh boy been here before with PC's in a room. Pull up the chip temp on the towers and see what you have there I know mine run about 115 120 when its on + 3 fans in it blowing out the hot air.

ED:thinker:

You're right Ed. I looked it up, it's a 15 SEER all right. The blower is for the 4 ton size, I asked about that one. You're right, we're getting about 110 out of each tower...
I really need some advice on what to say to this company. At this point I'm not getting calls back...
I was promised that our house would be cold. I knew I wouldn't get 70 degrees inside when it's 106 outside, but when I can't get below 82 in the coolest parts of the house...
I was PROMISED I'd see a big savings on the energy bill - I'm REALLY dissappointed with that. It's running constantly (even though it's not over 100) - and in our area there are LOTS of 98-102 degree days... I've been carefully checking the KW meter and we are using MORE power than before. We were close to 102 kw per day and now we're at 110-120 per day. We were running our old crusty unit from about 11am to about 10pm on days around 100 degrees, and running the house fan at night. Now we have the house closed up and letting the Trane run when it needs it to keep the temps around 80 (which ends up being the same time period as before with our old unit (10am to around 10 pm, and then cycles at night).
I just need to know what to say to these people, what is reasonable. I don't know or understand the all the theory, just what I was promised - 50% savings over our old unit, and our house at 80 degrees. I was SOO clear before the job was started - over and over - if that won't work, or it can't be done we'd wait unitl we had the money to "do it right." I tried so hard to make that understood.
Thanks SOOO much for helping!
Joe

According to my calculations you should have a 4.5 ton unit. 3.5 ton is very borderline for the size of your house. I wouldn't have gone lower than a 4 ton in a 1700 sq. ft. house.

According to my calculations you should have a 4.5 ton unit. 3.5 ton is very borderline for the size of your house. I wouldn't have gone lower than a 4 ton in a 1700 sq. ft. house.
That seems like the only thing that's left... Like today - the temps didn't get all that high - like 105, and by 9:00pm the outside temp was 89. Yet, my house was STILL 82 degrees inside and the A/C was running constantly all day without a break. I finally turned on the whole house fan and gave up.

Joe